title: The effect of antiepileptic drugs on thyroid function in children.
abstract: BACKGROUND
  Limited and conflicting data exist for the influence of antiepileptic drugs on thyroid function in children.
  
  
  OBJECTIVE
  The aim of this study was to investigate the effects of phenobarbital, valproate, carbamazepine, oxcarbazepine, and levetiracetam monotherapy on thyroid function in daily clinical practice during a 12-month treatment period.
  
  
  METHODS
  A total of 223 children (103 females and 120 males) with new onset and controlled epilepsy treated with valproate (n=129), phenobarbital (n=33), carbamazepine (n=36), oxcarbazepine (n=14), levetiracetam (n=11) were enrolled in the study. Serum free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels were measured before and at first, sixth and twelfth months of therapy.
  
  
  RESULTS
  At baseline, average fT4 and TSH concentrations were not different between the drug groups. Valproate-treated patients had decreased fT4 and increased TSH levels at months 1, 6, and 12. Carbamazepine-treated patients had decreased fT4 levels at months 1, 6, and 12 and increased TSH levels at months 1, and 6. Phenobarbital-treated patients had decreased fT4 levels at months 1, and 6, and increased TSH levels at months 6 and 12. Oxcarbazepine-treated patients had decreased fT4 levels at month 1. Levetiracetam-treated patients showed no significant change of fT4 and TSH at any times. The frequency of subclinical hypothyroidism at month 12 was 28% in valproate, 21.4% in oxcarbazepine, 18.2% in phenobarbital, 13.9% in carbamazepine, and 0% in levetiracetam groups.
  
  
  CONCLUSIONS
  Our data suggest that all antiepileptic drugs studied except levetiracetam had varying degrees of deleterious effects on thyroid function.
authors.affiliation: Department of Pediatric Neurology, Dr. Behçet Uz Children's Hospital, Izmir, Turkey. Electronic address: drunsalyilmaz@yahoo.com.
authors.forename: Unsal
authors.initials: U
authors.lastname: Yılmaz
authors.affiliation: Department of Public Health, Dokuz Eylul University Hospital, Izmir, Turkey. Electronic address: tuba.yilmaz@deu.edu.tr.
authors.forename: Tuba Sevim
authors.initials: TS
authors.lastname: Yılmaz
authors.affiliation: Department of Pediatric Neurology, Dr. Behçet Uz Children's Hospital, Izmir, Turkey. Electronic address: akincigulcin@gmail.com.
authors.forename: Gülçin
authors.initials: G
authors.lastname: Akıncı
authors.affiliation: Department of Pediatric Endocrinology, Dr. Behçet Uz Children's Hospital, Izmir, Turkey. Electronic address: hanilkorkmaz@gmail.com.
authors.forename: Hüseyin Anıl
authors.initials: HA
authors.lastname: Korkmaz
authors.affiliation: Department of Pediatric Neurology, Ege University Hospital, Izmir, Turkey. Electronic address: hasan.tekgul@ege.edu.tr.
authors.forename: Hasan
authors.initials: H
authors.lastname: Tekgül
mesh_terms: D000293:Adolescent; D000927:Anticonvulsants / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013960:Thyroid Function Tests / Q000379:methods; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D013974:Thyroxine
keywords: AED; Antiepileptic drugs; Children; Subclinical hypothyroidism; TSH; Thyroid function; antiepileptic drug; fT4; free thyroxine; thyroid stimulating hormone